"It would please me no end," she said, as I registered on my face precisely the amount of sympathy I felt for her outfit, "if you wouldn't flounce around this place in your nightclothes!"Philip Roth, Letting Go

Origin of flounce

1535-1545

Flounce may have emerged from the Scandinavian flunsa, "to plunge, hurry," but the first record of these is 200 years later than the English word. The English bounce may be an influence.